Question 446322
Let x m be the width of the table.
Let x+4 m be the length of the table.
...
{{{l*w=A}}}
{{{(x+4)(x)=77}}}
{{{x^2+4x=77}}}
{{{x^2+4x-77=0}}}
*[invoke quadratic "x", 1, 4, -77 ]
Since the answer must be positive,
x=7
x+4=11
Therefore the dimensions of the table are 7m by 11m.